Rotary printing press



H. J. LUL-:HRS 2,076,241

ROTARY PRINTING PRESS April 6, 1937.

Filed April 3,' 19.35V 2 Sheets-Sheet 1 Mm 1N VENTOR.

ATTORNEYS April 5, 1937. H. J. LuEHRs 2,076,241

ROTARY PRINTING PRESS BSheets-SheetiB Filed April 3, 1935 INVENTOR.

ATTORNEYS Patented Apr.. i937 1 STATES PATENT OFFICE ROTRY PRINTING PRESS Application April 3, 1935, Serial No. M385 6 Claims.

'lhe object of my invention is to provide novel and effective means for raising and lowering the impression roll and for automatically controlling its printing pressure on the design cylinder.

My invention includes, generally, a design cylinderx an impression roll, means for raising and lowering the impression roll, and means for automatically controlling the printing pressure between the design cylinder and impression roll.

My invention more specically includes motor means for raising and lowering the impression roll and means for automatically stopping the motor when the printing pressure between the design cylinder and impression roll has reached a predetermined point.

My invention still more specifically includes an impression roll mounted in a main head sliding in the main frame, a back-up roll carried by an auxiliary head having a limited sliding movement in the main head, and means acting through the auxiliary head and its back-up roll for bringing the impression roll into coaction with the design cylinder with a predetermined printing pressure.

A practical embodiment of my invention is represented in the accompanying drawings, in which Fig. 1 represents so much of a rotary intaglio web printing press in side elevation as includes my invention;

Fig. 2 represents a transverse vertical section taken in the plane of the line II-II of Fig. 1, looking in the direction of the arrows;

Fig. 3 represents a detail longitudinal vertical section taken in the plane of the line III-III of Fig. 2, looking in the direction of the arrows;

Fig. 4 represents a detail horizontal section taken in the plane of the line IV-IV of Fig. 3, looking in the direction of the arrows;

Fig. 5 represents a detail section similar to Fig. 3 with the parts in the positions they assume when pressure has been removed from the im pression roll 6;

Fig. 6 represents a detail horizontal section taken in the plane of the line VI--VI of Fig. 1, looking in the direction of the arrows; and

Fig, '7 represents the wiring diagram of the operating control for the motor.

The side frames of the printing press are denoted by I, in which side frames the shaft 2 of the design cylinder 3 is rotatably mounted.

The main sliding head 4 is slidably mounted in the side frames I and it is guided therein by the gibs 4*, in which head the shaft 5 of the impression roll 6 is mounted. The shafts 1 and 8 of the web guide rolls 9 and I0 are also rota tably mounted in the main sliding head 4 so as to move with the impression roll 5 toward and away from the design cylinder 3.

The auxiliary sliding head I I is slidably mount- 5 ed for a limited movement in the main sliding head 4, in which auxiliary sliding head the shaft I2 of a back-up roll I3 is rotatably mounted. The sliding movement of the auxiliary head Within the main head is limited, as, for instance, by the m adjusting screws I4 carried by the main sliding head 4. Non-rotatable screw-threaded impression screws I5 extend upwardly from the auxiliary sliding head by means of whichimpression screws the auxiliary head II and the main 1;) head l are raised and lowered with a lost motion connection between the auxiliary and main heads; said heads being guided in their respective side frames by means of the gibs 4*.

The means which I have shown for raising and lowering the non-rotatable impression screws I5 to thereby raise and lower the impression and back-up rolls, is as follows:

Wide faced helical gears I6 are threaded upon the impression screws I5, which gears are located normally in the bottoms of vertical chambers II in the side frames I. Sliding collars I8 surround the impression screws I5 within the chambers I1 above the wide faced helical gears I6. Between these collars I8 and screw-threaded caps I9, which close the upper ends of these chambers I1, there are interposed coil springs 2li surrounding the said impression screws I5. These screwthreaded caps I9 serve to adjust the tension of these coil springs 20.

A divided cross shaft 2I, 22 is mounted in the side frames I, which cross shaft is provided with worm gears 23 meshing with the impression screw helical gears I6. A manually releasable clutch 24 serves to removably lock the cross o shaft members 2I and 22 together. These cross shaft members are provided with hand wheels 25 and 26 respectively, for manual operation of the divided cross shaft from either side of the machine or for the independent manual opera- 4- tion of the cross shaft members when unlocked from each other.

A reversing electric motor 21 is mounted on a platform 28 carried by one of the side frames I. The motor shaft 29 carries a pulley 30 which 50 drives a belt 3| passing around a pulley 32 locked by a shear pin 33 to a collar 34 fast on the cross shaft member 22. A limit switch 35 is located in position to automatically operate to shut off the current from the motor 21 when the desired Cil .switch 41. A relay 50 printing pressure is obtained between the impression and design cylinders by the upward movement of the impression screw gears and sliding collars I8, and consequent compression of the coil springs 20. To accomplish this result one of the spring pressed sliding collars I8 is connected through a key 36, a bracket 31 and a link 38 with one arm 39 of a rock lever pivoted at 40 on one of the side frames I, the other arm of which rock lever is developed into a pointer 4I. The lever arm 39 has a cam projection 42 which is located in position to engage and throw the switch 35 to cut oli the current from the motor 21 when the printing pressure reaches a predetermined point. Another limit switch 43 is arranged in position to be engaged by a cam 44 carried by the main sliding head 4 to out oil the current from the motor 21 when the limit of upward movement of the main and auxiliary heads, with their rolls, has been reached.

The manually operated electric control for the reversing motor 21 includes the following elements:

A switch 45 is provided for running the moto-r in a direction to lower the main and auxiliary heads with their rolls. A switch 46 is provided for running the motor in the opposite direction to raise the main and auxiliary heads with their rolls. A third switch 41 is provided for stopping the motor at any time. A relay 48 and contact switch 49 is controlled by the switch 45 and the and contact switch 5I is controlled by the switch, 46 and the switch 41. These parts and their circuits are of well known and approved construction and will not be more specifically described herein.

In operation: Let it be assumed that the down switch 45 has been closed to cause the motor 21 to rotate the helical gears I6 on the impression screws I5 by means of the worm gears 23 on the divided cross shaft 2 I, 22, to lower the main and auxiliary heads 4 and II respectively, and their rolls from the position shown in dotted lines in Fig. 1. After the impression roll 6 has been brought into contact with the design cylinder 3 and the back-up roll I3 has been brought into contact with the impression roll 6 the further rotation of the helical gears I6 will cause them and the collars I8 to move bodily upward on the impression screws I5 within the chamber I1. This upward movement of the helical gears I6 and collars I8 will compress the coil springs 20 and thereby add pressure through the back-up roll I3 to the impression roll 6 to obtain the desired printing pressure between the impression roll and design cylinder. When the desired printing pressure has been obtained the limit switch 35 is opened by the cam 42 thus automatically shutting the current 01T from the motor 21.

When it is desired to raise the main and auxiliary heads with their rolls the switch 46 is closed to start the motor in the reverse direction, the first eiect being to cause the helical gears I6 and their collars I8 to travel downwardly on the impression screws I5 and release the extra tension on the coil spring 20. The next eiTect will be to cause the upward movement of the impression screws I5 and thereby the preliminary limited upward movement of the auxiliary head with its back-up roll I3. The next effect will be to combine upward movements of the main and auxiliary heads with their rolls.

When the main and auxiliary heads, with their rolls, reach the limits of their upward movement the limit switch 43 is opened by the cam 44, thus cutting the current off from the motor 21. It will be understood that the motor may be stopped at any time by the switch 41.

It will be noted that the operative connection between one of the spring pressed collars I8 and the arm 39 of the rock lever pivoted at 4I) is such as to cause a very quick operation of the switch 35 when the printing pressure of the impression roll reaches a predetermined point.

It will also be noted that the hand wide faced helical gears I 6 is selected with respect to the direction of rotation of the driving worm gears 23 to cause the threads of the helical gears to run away from the threads of the Worm gears when the helical gears are started on their upward movement against the pressure of the springs 20 as the impression roll comes in contact with its design cylinder. This will reduce the peripheral velocity of the helical gears proportionately to said upward motion at the time when an additional load is imposed upon the worm gears due to the increasing pressure of the said springs 20. 'I'his reduced ratio of the Worm drive while the wide faced helical gears I6 are moving upwardly is a distinct advantage in the operation of the mechanism.

It is evident that various changes may be resorted to in the construction, iorm and arrangement of the several parts without departing from the spirit and scope of my invention, and hence I do not intend to be limited to the particular embodiment herein shown and described, but

What I claim is:

1. In a rotary intaglio printing press, a design cylinder, a main sliding head, an impression roll carried thereby, an auxiliary head having a limited sliding movement in the main head, a back-up roll carried by the auxiliary head, and means for bringing the impression roll into coaction with the design cylinder comprising non-rotatable impression screws carried by the auxiliary head, gears threaded on the impression screws, and a motor driven cross shaft having gears meshing with the impression screw gears.

2. In a rotary intaglio printing press, a design cylinder, a main sliding head, an impression roll carried thereby, an auxiliary head having a limited sliding movement in the main head, and means for bringing the impression roll into coaction with the design cylinder at a predetermined pressure comprising spring pressed nonrotatable impression screws carried by the auxiliary head, gears threaded on the impression screws, and a motor driven cross shaft having gears meshing with the impression screw gears.

3. In a rotary intaglio printing press, a. design cylinder, a main sliding head, an impression roll carried thereby, an auxiliary. head havof the ing a limited sliding movement in the main head,

and means for bringing the impression roll into coaction with the design cylinder comprising non-rotatable impression screws carried by the auxiliary head, gears threaded on the impression screws, a divided cross shaft having gears meshing with the impression screw gears, a releasable clutch connecting the cross shaft members, and a motor for driving the cross shaft,

4. In a rotary intaglio printing press, a design cylinder, a main sliding head, an impression roll carried thereby, an auxiliary head having a limited sliding movement in the main head, and means for bringing the impression roll into coaction with the design cylinder comprising nonrotatable impression screws carried by the auxiliary head, gears threaded on the impression screws, a divided cross shaft having gears meshing with the impression screw gears, a releasable clutch connecting the cross shaft members, and a motor. for driving the cross shaft, said cross shaft being also capable of manual manipulation.

5. In a rotary intaglio printing press, a design cylinder, a main sliding head, an impression roll carried thereby, an auxiliary head having a limited sliding movement in the main head, and means for bringing the impression roll into coaction with the design cylinder comprising non-rotatableA impression screws carried by the auxiliary head, wide faced helical gears threaded on the impression screws, springs yieldingly holding the impression screw gears at the limits of their downward movements and a motor driven shaft having worm gears meshing with the impression screw gears.

6. In a rotary intaglio printing press, a design cylinder, a main sliding head, an impression roll carried thereby, an auxiliary head having a limited sliding movement in the main head, and means for bringing the impression roll into coaction with the design cylinder comprising non-rotatable impression screws carried by the auxiliary head, wide faced helical gears threaded on the impression screws, springs yieldingly holding the impression screw gears at the limits of their downward movements and a motor driven shaft having worm gears meshing with the impression screw gears, saidV worm gear drive prol viding a. reduced r-atio as the impression screw gears are moved upwardly against the pressure of their springs.

HANS J. LUEHRS. 

